We are, always and everywhere, self-conscious of how we differ. Search your memory for a social situation in which you were the only person of your gender, sexual orientation, ethnicity, or body type. Perhaps you were the only woman in a group of men, or the only straight person at an LGBTQ gathering.

Recalling that situation . . .

Were you self-conscious about your identity?

How did others respond to you?

How did your perceptions of their responses affect your behavior?

Differences determine our “spontaneous self-concepts.” If you recalled being very aware of your differences, you are not alone. As social psychologist William McGuire long ago noted, we are conscious of ourselves “insofar as, and in the ways that” we differ. When he and his co-workers invited children to “tell us about yourself,” they mostly mentioned their distinctive attributes. Redheads volunteered their hair color, foreign-born their birthplace, minority children their ethnicity. Spontaneous self-concepts often adapt to a changing group. A Black woman among White women will think of herself as Black, McGuire observed. When moving to a group of Black men, she will become more conscious of being a woman.

This identity-shaping phenomenon affects us all. When serving on an American Psychological Association professional task with 10 others—all women—I immediately was aware of my gender. But it was only on the second day, when I joked to the woman next to me that the bathroom break line would be short for me, that she noticed the group’s gender make-up. In my daily life, surrounded by mostly White colleagues and neighbors, I seldom am cognizant of my race—which becomes a prominent part of my identity when visiting my daughter in South Africa, where I become part of a 9 percent minority. In the U.S., by contrast, a new Pew survey finds that 74 percent of Blacks but only 15 percent of Whites see their race as “being extremely or very important to how they think of themselves.”

Our differences may influence how others respond to us. Researchers have also noted a related phenomenon: Our differences, though mostly salient to ourselves, may also affect how others treat us. Being the “different” or “solo” person—a Black person in an otherwise White group, a woman in a male group, or an adult in a group of children—can make a person more visible and seem more influential. Their good and bad qualities also tend to be more noticed (see here and here).

If we differ from others around us, it therefore makes adaptive sense for us to be a bit wary. It makes sense for a salient person—a minority race person, a gay person, or a corpulent person—to be alert and sensitive to how they are being treated by an interviewer, a police officer, or a neighbor. Although subsiding, explicit prejudices and implicit biases are real, and stereotypes of a difference can become a self-fulfilling prophecy.

Sometimes our perceived differences not only influence how others treat us, but also how we, in turn, respond to them. In one classic experiment, men students conversed by phone with women they mistakenly presumed (from having been shown a fake picture) were either unattractive or attractive. The presumed attractive women (unaware of the picture manipulation) spoke more warmly to the men than did the presumed unattractive women. The researchers’ conclusion: The men’s expectations had led them to act in a way that influenced the women to fulfill the belief that beautiful women are desirable. A stereotype of a difference can become a self-fulfilling prophecy.

Our acute self-consciousness of our differences can cause us to exaggerate or misinterpret others’ reactions. At times, our acute self-consciousness of our difference may have funny consequences. Consider of my favorite social psychology experiments demonstrating the influence of personal perception of differences. In the first, which showed the “spotlight effect,” Thomas Gilovich and Kenneth Savitsky asked university students to don a Barry Manilow T-shirt before entering a room with other students. Feeling self-conscious about their difference, those wearing the dorky T-shirt guessed that nearly half of their peers would notice the shirt. Actually, only 23 percent did. The lesson: Our differences—our bad hair day, our hearing loss, our dropping the cafeteria plate—often get noticed and remembered less than we imagine.

In another favorite experiment—one of social psychology’s most creative and poignant studies—Robert Kleck and Angelo Strenta used theatrical makeup to place an ear-to-mouth facial scar on college women—supposedly to see how others would react. After each woman checked the real-looking scar in a hand mirror, the experimenter applied “moisturizer” to “keep the makeup from cracking”—but which actually removed the scar.

So the scene was set: A woman, feeling terribly self-conscious about her supposedly disfigured face, talks with another woman who knows nothing of all this. Feeling acutely sensitive to how their conversational partner was looking at them, the “disfigured” women saw the partner as more tense, patronizing, and distant than did women in a control condition. Their acute self-consciousness about their presumed difference led them to misinterpret normal mannerisms and comments.

The bottom line: Differences define us. We are self-conscious of how we differ. To a lesser extent, others notice how we differ and categorize us according to their own beliefs, which may include stereotypes or unrealistic expectations. And sometimes, thanks to our acute sensitivity to how we differ, we overestimate others’ noticing and reacting. But we can reassure ourselves: if we’re having a bad hair day, others are unlikely to notice and even less likely to remember.

(For David Myers’ other essays on psychological science and everyday life, visit TalkPsych.com.)